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Would anyone be able to offer an informed opinion please: is there a benefit, or is it a con? I mean the variety which you pour into your fuel tank (or others?). I've had two injectors replaced, and am interested in maximising the life of them given the eye-watering cost to replace on this common rail system.
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What did you pay for replacing the injectors and what car are we talking about here.
Millers diesel additive gets good press on this forum but I've not used it myself.
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Injectors on Mercedes-Benz CDI engines, a Sprinter in my own case. Up until recently they were around £250 each depending which one was required, but I understand the price has come down now to around £130 each.
Injector reliability has been the achilles heel of these engines. Everyone I have asked who runs an MB CDI commercial has had injectors replaced. They claim to have solved the problem now - we shall see...
I'm enquiring about cleaning additives, rather than ones which may (or may not!) have other benefits. Will look at Miller's site, thanks.
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I've used Millers products and I am confident they work well.
Ironic isn't it though, we all buy diesels primarily for the supposed 30% fuel saving over equivalent petrol models. Then we have the oil companies (not the chancellor this time) ripping us off an extra 2-3p per litre for the stuff, as well as the extreme complexity of the newer diesels being more expensive to service and repair than their petrol equivalents.
I drive a diesel but I'm beginning to have my doubts ??????
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Dont blame oil companies. It is the Chancelor - diesel is taxed higher than petrol
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Indeed it is. Just back from a few days in Holland, where diesel is ~E0.85/litre and petrol ~E1.20. Similar in France and Ireland, I believe.
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I reckon a splash of petrol in the tank, like a few % would probably suffice!
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I think this a durability problem on these injectors. Cleaning them won't make any difference. The pressure sensor on the rail also packs up - ECU goes into 'default' mode which gives drivability problem and poor starting.
You are right that you save a bit on the fuel but pay it back in repair costs - these modern high pressure diesels are just so complex - a far cry from the old Merc OM Diesels!
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Several RAC men have told me that the engine of my 10 year old Audi 80 TDi is much more reliable and trouble free than the new Audi common rail engines for the reasons that they are indeed extremely complex, so complex, in fact, and with such high pressures, that nine times out of 10 the RAC can't help with engine problems as the car has to go into an Audi workshop. Some RAC men have had accidents with these pressures, one losing a finger!
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Pressure is about 1800psi on a common rail fuel system. Quite high!
Not sure about a dash of petrol in the tank. Mercedes-Benz say that any petrol in the diesel fuel system wrecks the seals and the high speed fuel pump, causing major havoc.
I agree that it is more symptomatic of a design problem. My thoughts were simply to see if there was anything I could do to extend the injectors' life.
Diesel prices abroad are catching up with the UK's incidentally...
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I can concur with the above. At my place of work (Ambulance service)where we run a fleet of Merc diesels, they are all slowly needing the injectors replacing.
At my place of work our vehicle failed at about 30,000 miles. Another amulance failed last week at a neighbouring station, with probably 50,000 miles on (not absolutely sure).
Symptoms are, runs fine, but occasional fail to start which rapidly gets worse, until it is "dead". Apparently with only one injector faulty, they just don't start.
Reggie
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Pressure is about 1800psi on a common rail fuel system. Quite high!
Bit higher than that mate. On Bosch 2nd and 3rd generation systems the pressure is 1600Bar - that's about 24000psi !!
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>Pressure is about 1800psi on a common rail fuel system.
No, pressure is about 1650 BAR eg 24,000 psi!!
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RichardW
Is it illogical? It must be Citroen....
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I don't service diesels but am well aware than the pressure is high enough to cause serious injury; therefore I'm surprised that RAC mechanics have have injured themselves whilst working on diesel injection systems?
I did 75k in a VAG diesel, had a few problems but non-related to the injection system. In fact not aware of any injector problems relating to VAG engines, certainly on this site and the VAG PD engines have the highest injector pressures.
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It has been mentioned in the past here that VAG diesel injectors can produce an uneven spray pattern at around 75 - 100k that can result in ovalisation of the bores.
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Please see the following URL www.inlandrevenue.gov.uk/budget2004/pn03.htm
It will be seen that the duty on standard unleaded petrol was exactly the same as petrol, admittedly ULSP was 1p less, but some garages were charging 3p per litre more for diesel.
So the oil companies are still to blame.
It will remain to be seen how honestly the new duty rates rates are applied at the pumps.
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